US3895347A - System for transmitting information of reduced pneumatic pressure of tire - Google Patents

System for transmitting information of reduced pneumatic pressure of tire Download PDF

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Publication number
US3895347A
US3895347A US491902A US49190274A US3895347A US 3895347 A US3895347 A US 3895347A US 491902 A US491902 A US 491902A US 49190274 A US49190274 A US 49190274A US 3895347 A US3895347 A US 3895347A
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United States
Prior art keywords
antenna
wheel
radiation
electromagnetic wave
tire
Prior art date
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Expired - Lifetime
Application number
US491902A
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English (en)
Inventor
Takashi Takusagawa
Akira Fujikawa
Akira Matsuda
George Matsuura
Kenzo Nakanishi
Hideo Togawa
Yasuaki Hanasaka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bridgestone Corp
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Bridgestone Corp
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Filing date
Publication date
Priority claimed from JP10196273A external-priority patent/JPS5441338B2/ja
Priority claimed from JP628774A external-priority patent/JPS5621197B2/ja
Application filed by Bridgestone Corp filed Critical Bridgestone Corp
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Publication of US3895347A publication Critical patent/US3895347A/en
Anticipated expiration legal-status Critical
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C23/00—Devices for measuring, signalling, controlling, or distributing tyre pressure or temperature, specially adapted for mounting on vehicles; Arrangement of tyre inflating devices on vehicles, e.g. of pumps or of tanks; Tyre cooling arrangements
    • B60C23/02—Signalling devices actuated by tyre pressure
    • B60C23/04—Signalling devices actuated by tyre pressure mounted on the wheel or tyre
    • B60C23/0408—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
    • B60C23/0422—Signalling devices actuated by tyre pressure mounted on the wheel or tyre transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver characterised by the type of signal transmission means
    • B60C23/0427—Near field transmission with inductive or capacitive coupling means
    • B60C23/0428—Near field transmission with inductive or capacitive coupling means using passive wheel mounted resonance circuits
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L17/00—Devices or apparatus for measuring tyre pressure or the pressure in other inflated bodies

Definitions

  • ABSTRACT A system for transmitting information of reduced pneumatic pressure of tires comprising an electromagnetic wave radiation mechanism of an electric field excitation system and at least one receiver antenna of an electromagnetic field sensing type for sensing a polarized wave of an electromagnetic field radiated from the radiation mechanism.
  • the radiation mechanism includes an electromagnetic wave radiation member consisting of a substantially concentric metal body opposedly and substantially provided on each axle of a plurality of tire wheels for actuating as an electric dipole together with the wheels and an oscillator electrically coupled to the radiation member and energized by a switch actuated in response to reduced pneumatic pressure of tire.
  • the receiver antenna is provided in the space between the ground surface and the lower surface of the bottom plate of the car body in order to screen external noise waves.
  • the present invention relates to a system for transmitting information of reduced pneumatic pressure of tire by sensing reduction of pneumatic pressure ofa tire and by informing the thus sensed information to an operator when the pneumatic pressure of any one of tires of vehicles is reduced by some reason while running or parking.
  • broadcast waves, communication waves and other noise waves are stronger than the electromagnetic waves from the oscillators to be used. so that it becomes difficult to discriminate a desired signal from others. and thus erroneous information is produced.
  • a wave radiation mechanism of a conventional transmitter for sensed information of reduced pneumatic pressure shown in FIG. I consists of a signal oscillator l, a sensing switch 2 for closing its contacts when the internal pressure of a tire is lowered to less than a predetermined value, an electric power supply source 3 for suppplying voltage to the oscillator through said switch 2 at the closing thereof. and a loopshaped electromagnetic radiation member. i.e., a radiation coil 4, for transmitting the output of said oscillator 1.
  • This oscillator I is provided with a resonance circuit 5 for carrying out oscillation and for amplifying an oscillated signal and an output coil 6 magnetically coupled thereto, so that voltage induced in the coil 6 is sup plied through a conductor wire 7 to said electromagnetic radiation member 4, so as to flow an AC current therethrough and to radiate an induced electromagnetic field from the elctromagnetic radiation member 4.
  • the loop-shaped electromagnetic radiation member 4 of such wave radiation mechanism is actually constructed in such a manner that its diameter is made larger than the outer diameter D of a rim II ofa disc wheel 10 and is embedded in a ring 12 made of rubber or the like, and an inner peripheral portion I3 of this rubber ring I2 is pressed between an inner wall portion [4 of the rim II and a contact surface 16 of the rim 1] of a tire 15. Accordingly, in case rim 1] and then the tire I5 is mounted to the rim 11,
  • the internal pressure sensing switch 2, the power supply source 3 and the oscillator 1 are not illustrated, but they should be provided on the surface portion of the wheel and protected by a wheel cap or the like. Therefore, it also becomes difficult to fit these components to the wheel.
  • the conductor wire 7 between the output coil 6 and the loop-shaped radiation coil 4 should be introduced into the rear surface side from the front surface side of the wheel through a gap provided in a por tion of the wheel under the rim ll therof. so that the fitting operation thereof becomes troublesome.
  • an electromagnetic wave radiation mechanism of a conventional device shown in FIG. 3 is composed by providing an electromagnetic wave radiation member or radiation members 4' at one or several portions of a rim bottom portion [9 of the wheel 10 and adjacent the rim bottom portion so as to radiate electromagnetic waves from an oscillator through a rubber layer of the tire l5.
  • the electromagnetic wave radiation mechanism having such construction requires a suitable machining operation. i.e., machining of a screw hole 20, for securing the radiation member around the rim bottom portion 19, and the position for fitting the radiation member is so positioned that a plurality of radiation members can precisely keep their static and dynamic balancing to rotation of wheels. or in case of fitting one radiation member. it is necessary to fit a balance weight-having the same mass as the radiation member at the position diametrically opposed to the wheel of the radiation member.
  • an antenna mechanism for receiving an electromagnetic wave from an electromagnetic wave radiation mechanism in case of providing a receiver antenna corresponding to electromagnetic wave radiation member of each wheel, the electromagnetic wave (or inductive electromagnetic wave) from the radiation member is absorbed by metal members such as a mudguard or the like provided near the tire, so that it is necessary to set the receiver antenna in the space where the shilding and absorption hardly occur, and very near to each radiation member.
  • a receiver antenna 21 i.e., a senser coil for reception of the wave is fitted to a part of a wheel suspension portion such as a housing of the hub 17 which is at rest against rotation of wheels, and is not changed crossing of magnetic flux against vertical movement of wheels or against angle displacement of front wheels, i.e., a peripheral portion of a brake drum 22 by means of a metal fixture.
  • the senser coils 21 are secured as described above to the radiation coils 4 of wheels, respectively, and the output lead wires of the senser coil 21 are passed through the car body or connected to a receiver along the bottom portion of the car body.
  • the receiver of the aforementioned conventional device has the following defects.
  • the radiation coil 4 and the senser coil 21 are magnetically coupled with each other, and when these coils are so mounted that relative intervals thereof are varied while running, the degree of magnetic coupling is varied, so that it is impossible to transmit signals with satisfaction.
  • the front wheels of the vechicle are accompanied by angle displacement for steering, so that mounting of these coils is very difficult.
  • the induction magnetic field of the radiating coil 4 has sharp directivity, and large magnetic absorption and attenuation at the steel portions such as wheels, hubs or the like, so that large electric supply power is required for excitation of the coil.
  • the radiation coil inevitably has the outer diameter larger than the diameter of the rim and it cannot be avoided to arrange the radiation coil along the tire side wall of the rear surface of the wheel. As a result, repair or exchange of a punctured tire becomes very inconvenient.
  • a receiver for receiving the induced voltage of the antenna regarded as the same potential as the ground surface in relation to the incoming wave through the electrostatic capacitance between the car body and the ground surface or for receiving the induced current flowing through said electrostatic capacitance from the antenna to the ground surface.
  • the electromagnetic wave from the radiation member of the oscillator near the wheel the electromagnetic wave from each radiation member is reflected from or absorbed in the side surface of the car body so that radiation energy flowed to a desired receiver antenna becomes a little.
  • the electromagnetic waves for broadcasting and communication and other incoming noise waves are received by the receiver with large energy.
  • the ratio of the signal component of the elctromagnetic wave from said radiation member and the signal component (noise signal) of other incoming waves becomes lessened and discrimination of a desired signal becomes very difficult, so that stability of reception necessary for this kind of devices is spoiled.
  • One of various defects of the aforementioned device according to the conventional technique is that in case of utilizing an electric characteristic of the electromagnetic wave radiation member for the oscillator, i.e., induction magnetic field in radio engineering, the receiver antenna mechanism must be arranged near each radiation member of wheels. Therefore. in this point these defects cannot be avoided.
  • the electromagnetic wave radiated from the radiation member for the oscillator can be received, but the received energy is weakened as described in the foregoing.
  • An object of the present invention is to eliminate the aforementioned various defects and to provide a system for transmitting information of reduced pneumatic pressure of tires comprising a plurality of electromagnetic wave radiation members corresponding to each tire wheel and an antenna mechanism for reliably receiving electromagnetic waves from each radiation member.
  • Another object of the invention is to provide a system for transmitting information of reduced pneumatic pressure of tires. which can easily be mounted on the car body and manufactured inexpensively.
  • Further object of the invention is to provide a system for transmitting information of I reduced pneumatic pressure of tires, in which electromagnetic wave radiation having wide directivity can be possible by means of an oscillation circuit having low electric supply power, and instead of providing a number of sensing receiver coils corresponding to a number of wheels, only one antenna can receive information, and the system being easily mounted on the surface of a wheel.
  • the system for transmitting information of reduced pneumatic pressure of tires comprises an electromagnetic wave radiation mechanism of an electric field excitation system and a receiver antenna of an electric field sensing type or a magnetic field sending type.
  • the electromagnetic wave radiation mechanism includes an electromagnetic wave radiation member consisting of loop-shaped metal body opposedely provided on the wheel surface of a plurality of tire wheels and an oscillator coupled to the radiation member and energized in response to reduced pneumatic pressure of the tire.
  • the receiver antenna is provided in space between the surface of the ground and the lower surface of the bottom plate of the car body and sense a horizontally polarized wave of an electric field or a vertically polarized wave of a magnetic field radiated from said radiation mechanism, respectively.
  • the electromagnetic wave radiation member is a metal ring having a common axis to metal wheels for holding the tire.
  • the metal ring is electrically insulated and opposedely arranged to the metal wheel and is used as a radiation antenna for the output of an oscillator energized in response to reduced pneumatic pressure of the tire.
  • the metal ring is embedded in an annular insulator which is fitted to a rim of wheel.
  • FIG. 1 is a circuit diagram of a transmitter for reucked pneumatic pressure signals of tires according to a conventional system
  • H68. 2 and 3 are cross-sectional views of the conventional system
  • FIG. 4 is a schematic circuit diagram of transmitter of the system according to the present invention.
  • FIG. 5 is a cross-sectional view showing the positional relation of an electromagnetic wave radiation mechanism according to the present invention which consists of a tire wheel and an electromagnetic wave radiation member opposedly provided thereto;
  • FIG. 6 is across-sectional view showing another embodiment of the electromagnetic wave radiation mechanism according to the present invention.
  • FIG. 7A is a schematic side view showing a receiver antenna mechanism mounted at the bottom surface of a car body'
  • FIG. 7B is a schematic bottom view of the receiver antenna mechanism shown in FIG. 7A;
  • FIG. 8 is a plan view showing a receiver antenna of an electric field sensing type particularly a dipole antenna for use in the system according to the present invnetion;
  • FIG. 9 is a perspective view showing a receiver antenna of a magnetic field sensing type for use in the system according to the invention.
  • FIG. 10 is a fundamental view showing another embodiment of tire wheel provided with the transmitter device according to the invention.
  • FIG. II is a partially sectional view of the tire wheel provided with the transmitter device shown in FIG. 10',
  • FIG. 12 is a partially perspective view of wheel provided with the transmitter shown in FIG. 11;
  • FIG. 13 is a view showing distribution of electric field in case of cutting the radiation mechanism in the plane inclusive of the wheel of the vehicle.
  • FIG. 14 is an explanatory view showing strength of e l ectric field which is received by a receiver antenna AB from the center (0) of a radiation member.
  • An electromagnetic wave radiation mechanism of the system comprises an oscillator l and an electromagnetic wave radiation member 4 in each wheel.
  • said radiation mechanism means a mechanism comprising a tire wheel 10 and a radiation member 4 for forming an electric dipole.
  • the radiation member 4 consisting of a metal body is electrically connected to the output side of the oscillator I through a conductor wire 7.
  • the oscillator l is further connected to a switch 2 having an electric contact 2a which closes when a pneumatic pressure of the tire is lowered to less than predetermined value and an electric power supply source 3.
  • the oscillator I operates when the contact 211 is closed by lowering the pneumatic pressure of the tire and a closed circuit containing the power supply source 3 is formed. The operation of the oscillator is continued while the contact 2a is closed. Then, an electromagnetic wave is radiated from the radiation member 4 by this oscillation.
  • the radiation member 4 is arranged on the same axis as that of an axle at the position opposed to the surface of the wheel l0, so as to form an electric dipole between the radiation member 4 and the surface of the wheel 10 and to connect the wheel surface to the surface ofthe ground (connect a feedback path 8 of the oscillator to the wheel).
  • the power supply source 3 is preferablly a small mercury dry cell.
  • the elctromagnetic radiation body can be formed into a dome. a loop, a ring or a disc having no hole, or a polygon, and can concentrically be arranged and fitted to the wheel. Accordingly, the shape of the enveloping surface of an electric line of force 9 formed between the surface of the radiation member 4 and the wheel surface becomes dome-shape or cylindrical under the condition that it coindides with the axis of the wheel.
  • the more preferable enveloping surface by means of the electric line of force is, as shown in another embodiment of FIG. 6, is obtained by providing a loop-shaped projection member 10a on the surface of the wheel 10 and by arranging the radiation member 4a opposedely thereto. Its shape is therefore cylindrical or drum-shape.
  • the loopshaped radiation member 4 or 40 has its axis coincided with the axis of the wheel and is provided opposedly to the surface of the wheel 10, so that lowering of the output of the oscillator caused by increasing electrostatic capacitance between a projection 10b of a supporting member of a bearing provided in the front wheels or the like of the vehicle and the radiation member 4 or 4a can be prevented. It means that the output of the electromagnetic wave radiation is made equal as possible as compared with the case of the surface of the wheel having no projection such as rear wheels.
  • a receiver antenna mechanism suitable for receiving the horizontally polarized wave of a radiation electric field from the electromagnetic wave radiation mechanism of the transmitter is arranged in the space sandwiched by a bottom plate 30 of a car body and the ground surface 31 at the position adjacent the bottom plate 30 and in flat plane 32 almost paralled to said bottom plate 30.
  • an antenna 33 is secured to the car body at a right angle between the front wheels and the rear wheels.
  • the antenna 33 receives an electric field wave component polarized in the direction at right angles to the forward direction of the vehicle
  • the antenna 33a secured parallel to the car body receives an electric field wave component polarized paralled to the forward direction of the vehicle.
  • These antennas 33 and 33a can be used separetely or together as an electrostatic field antenna.
  • the receiver antenna can be a crossed dipoles consisting of a pair of antennas 34a and 3412. Le. the so-called shortened type. which make the length of one segment shorter than or in a fraction of the wave length of the electromagnetic wave radiated from the radiation member 4.
  • FIG. 9 an embodiment of the receiver antenna having a mechanism different from the above electrostatic field receiver antenna is shown in FIG. 9.
  • the antenna in this embodiment is made by applying a winding 36 to a bar-shaped magnetic core 35 which has axis on a perpendicular dropped from the bottom surface of the car body onto the ground surface.
  • a metal plate for compensating the electrostatic potential caused by the electric field of the electromagnetic wave
  • an electrostatic shielding cylinder 37 having such a structure that a part of the periphery thereof is not short circuited against the induced voltage caused by the core 35.
  • Such magnetic field type antenna for obtaining the voltage induced in the winding 36 by a change of the flux passed through the magnetic core 35 at the output terminal 38.
  • Such magnetic field type antenna as shown in the drawing is provided at the middle of the front and rear wheels or at the rear of the rear wheels of the car body.
  • the electric lines of force form a drum-shaped by the loop-shaped projection 10a on the wheel surface. Therefore, the so-called electromagnetic wave is generated by groups of these electric lines of force. and three-dimensionally propagated around the dipole.
  • the electromagnetic wave radiation member consists of a loop-shaped radiation antenna 4h made of a metal wire as shown in FIG. It]
  • the radiation antenna 411 is embedded in a ringshaped insulator body I2 made of a material selected from hard plastics and hard rubbers or the like as shown in FIGS. II and 12,
  • the loop antenna 417 is arranged adjacent the outer wall of the rim II in the space of the outer wall portion of the rim.
  • the power supply source 3 and the oscillator l are accommodated in a part of the ring-shaped insulator body 12 as shown in FIG. II.
  • the power supply source 3 is preferablly a small mercury dry cell.
  • One end 5A of the resonance circuit 5 of the oscillator I is connected to the antenna 4h. while the other end 5B is grounded to the rim 1] by means of a grounded fixture (not shown) provided at a part of the insulator body 12.
  • the internal pressure sensing switch 2 of the tire is sccured to a valve and connected to the oscillator through the conductor wire as shown in FIG. I0.
  • the voltage of the power supply source 3 is applied to the oscillator l and a resonance voltage is generated between the terminals SA and 5B of the resonance circuit 5.
  • the terminal 58 is at grounded potential. so that the voltage applied to the terminal 5A. i.e., the antenna 412. is generated by the driving of a constant current from an active element for oscillation in a parallel circuit consisting of the coil 5L.
  • capacitor SC and the capacitance 4C provided that the value of electrostatic ca pacitance 4C of the wheel to the antenna 4! is Ca and the value of the leakage resistance 4R of the wheel to the antenna 412 is Ra.
  • the output voltage thereof is in proportion to Q of the coil 5L, i.e., the ratio of the reactance wL and the internal resistance re of the coil 5L, wL/re. so that in order to make L large. the even electrostatic capacitance of the wheel to the antenna should be made small, and in order to make the radiation efficiency of the antenna large, it is necessary to make the radiation effective area large.
  • the loop or ring-shaped antenna made ofa metal conductor according to the invention is to make the even electrostatic capacitance of the wheel to the ring conductor small and make the radiation area large by an envelope effect to the high frequency voltage, so that only a small power is required for electric field excitation, the directivity becomes maximum on the plane parallel to the bottom surface of the car body, and in the vehicle, the electromagnetic wave from the radiation antenna of each wheel can be received by only one receiver antenna.
  • the radiation antenna and circuit elements such as oscillator or the like inside the wheel cap, but if all the circuit elements are embedded in the ring-shaped insulator body I2 and in tegrated by arranging the mounting jig 39 to the outer wall portion of the rim 11 as shown in the present embodiment, not only detachability to the wheel 10 becomes very easy. but also connection of the internal pressure senser fitted to the valve with the transmitter becomes easy. In addition, there is another advantage that the outer diameter of the metal ring as a radiation antenna can be made large.
  • the electromagnetic wave three-dimensionally propagated around the dipole for one radiation mechanism is designated by cut by planes inclusive of axle of each wheel of the vehicle as shown in FIG. 13.
  • the forward directions by propagation of the electric field polarized wave of the electromagnetic wave along the x plane becomes radial around the radiation member, and thus groups of electric line of force (a) are estimated on any plane.
  • a receiver antenna 33 or 33a consisting of a straight metal conductor is placed at its center portion of diago nal lines of wheels in the .r-y plane or the parallel plane adjacent the v plane.
  • the antenna 33 receives the effecti mean electric field shown by a curved line portion MN which is extended along the mean intensity of electric line c of force is the electric l i nes a and b of force passing through the segment AB of the antenna for the electromagnetic wave radiated from the wave radiation mech anism of one of wheels and which is determined by the intersections of the mean intensity of electric line of force and the normal lines m and a through both ends A and B or the segment from the center 0 of the electromagnetic wave radiation member as shown in FIG.
  • the middle point P of the segment AT is at equal distances from the wave radiation mechanism of each wheel, so that the voltage induced in the antenna becomes almost equal even by any radiation member.
  • the anten n a 33a shown in FIG. 78 corresponds to the segment AB of the antenna shown in FIG. 14 rotated 90 around the middle point P. and the electric field intensity where the segment is positioned is slightly different from in the antenna 33, but the distance from each wave radiation member is same as that of the antenna 33, so that almost equal induced voltage for the electromagnetic wave from any wave radiation member can be obtained.
  • the receiver antenna consisting of two lines perpendicularly intersecting each other shown in FIG.
  • the phase of the potential or current of the middle points P and Q can be made an opposite pole relation which is phase shifted by l8(), so as to form a dipole antenna and a large antenna gain can be obtained as compared with the antenna 33 or 330.
  • a receiver antenna of magnetic field type will be explained hereinafter.
  • the antenna can receive a magnetic field polarized wave presenting in the vertical direction to the group of the electric lines of force on the .rplane and the electric field intensity is the strongest on the .rplane. so that it can easily be found that the magnetic field intensity at right angles thereto is also the strongest according to a well known therom of pointing.
  • the receiver antenna of magnetic field type is mounted vertical to the bottom plate 30 of the car body and at the central portion of the diagonal line of each wheel, a single antenna can equally receive magnetic field polarized waves from the radiation mechanism of each wheel at the magnetic field intensity corresponding to the aforementioned effective electric field intensity of the receiver antenna 33 or 33a of the electric field type.
  • the receiving function for the electromagnetic wave of the wave radiation mechanism is explained with reference to each embodiment of the antenna mechanism according to the present invention in the foregoing, and the effect for removing other electromagnetic waves transmitted from the radiation mechanism other than that of each antenna mechanism will be explained hereinafter.
  • the receiver antenna mechanism of the electric field type ac cording to the invention is arranged in the plane inclusive of each axle within the space between the bottom portion of the car body and the ground surface parallel thereto or along the plane adjacent the bottom portion of the car body, and the receiver antenna mechanism of the magnetic field type is so arranged that the barshaped antenna has the axial direction vertical to the plane of the bottom surface of the car body. Accordingly.
  • the electromagnetic wave from the radiation member in the space can be received by an antenna mechanism of one system with the strongest magnetic field intensity.
  • the communication or broadcasting wave is screened in said space from the antenna placed at this position through the electro static capacitance of the car body to the ground, so that the electric field intensity of the electromagnetic wave around the antenna is considerably reduced.
  • the car electrostatic capacitance of the antenna adjacent the bottom portion of the car body is considerably larger than the ground electrostatic capacitance of the antenna, so that the antenna per se becomes almost same potential as that of the car body. Therefore, the voltage induced by these undesirable incoming waves is reduced, and thus it has no influence as noises upon reception of the electromagnetic wave from the radiation mechanism of each desired wheel.
  • the electromagnetic noise wave generated by the vehicle itself is strongly present in the space extended from the lower opening portion of the engine room of the vehicle to the ground surface, and then such noise becomes disturbing in the receiver antenna arranged at the aforementioned position.
  • the mounting position of the receiver antenna mechanism is preferably shifted from the central position of the diagonal line of each wheel to the opposite side of the engine room.
  • An embodiment of this case (antennas 33b. 400 shown by a dotdash line in FIG. 7) belongs to the category of the present invention.
  • the electromagnetic wave radiation mechanism can radiate the electromagnetic wave with a constant intensity regardless of rotation and rest of wheels. and further radiate the strongest electric field polarized wave or magnetic field polarized wave in the vertical direction thereto on the plane inclusive of each axle or in the space between this plane and the bottom surface of the car body. Accordingly, if one system of the elec tric field type or magnetic field type receiver antenna mechanism is arranged in the space. any electromagnetic wave from any radiation member of the wheel can be received with almost equal electric and magnetic field intensity.
  • the ring-shaped or domeshaped radiation member is arranged on the same axis as that of the wheel by facing to the wheel surface, while the oscillator circuit and the power supply source are also accommodated in the central portion of the radiation member and integrally formed with each other, so that any fault caused by unbalanced mass to rotation of the wheels can be eliminated.
  • the device according to the present invention can easily be mounted by the use of a hub bolt for fitting the wheel of a vehicle or by operation similar to the fitting operation of the wheel cap.
  • the receiver antenna mechanism can receive the electromagnetic wave from the desired radiation member with the strong intensity of electric or magnetic field, and reduces unnecessary waves by screening effect provided by utilizing the electric ground characteristic of the car body, and can stabilize reception of desired electromagnetic wave.
  • the receiver antenna mechanism according to the present invention is not a conventional system for arranging a plurality of antennas but one system, so that the mounting of the antenna and the installation of the conductor wire to the receiver can be simplified.
  • the radiation antenna is a closed ring, but the present invention does not limit it thereto.
  • the radiation antenna can be a ring opened at one point.
  • the central point to the segment is made a contact with the output of 'the oscillation circuit. so that a standing wave is generated to the whole length of the ring and the voltage feeding can be formed, or one end of the open ring is ,connected to the tap down point of the oscillation coil L. so that current feeding can be formed.
  • the directivity of the radiation electric field becomes the strongest along the vertical plane to the bottom surface of the car body, but the effect thereof is as well as the aforementioned one.
  • the tire can be used as an insulator body for the aforementioned radiation antenna. However, even if it is embedded in the tire. the same effect as the aforementioned embodiment can be obtained.
  • a system for transmitting information of reduced pneumatic pressure of tires comprising an electromagnetic wave radiation mechanism of an electric field excitation system having an electromagnetic wave radiation member consisting of a substantially concentric metal body opposedly and substantially concentrically provided on each axle of a plurality of tire wheels for actuating as an electric dipole together with the wheels and having an oscillator electrically coupled to said radiation member and energized in response to reduced pneumatic pressure of tires; and at least one receiver antenna of an electromagnetic field sensing type provided in the space between the surface of the ground and the lower surface of the bottom plate of the car body for sensing a polarized wave of an electromag netic field radiated from said radiation mechanism in order to screen external noise waves.
  • said electromagnetic wave radiation body consists of a metal ring having a common axis to metal wheel for holding the tire, said metal ring is electrically insulated and opposedly arranged to said metal wheel, and is used as a radiation antenna for the output of an oscillator energized in response to reduced pneumatic pressure of the tire.
  • annular insulating body is detachably fitted to the rim of the'whe'el by means of a jig along the inner surface in the radial direction thereof.
  • receiver antenna is an antenna of an electric field sensing type for sensing a horizontally polarized wave of an electric field radiated from said electromagnetic wave radiation mechanism.
  • said receiver antenna is an antenna of a magnetic field sensing type for sensing a vertically polarized wave of a magnetic field radiated from said electromagnetic wave radiation mechanism.
  • said antenna of magnetic field sensing type is consisted of a bar-shaped magnetic core. a sense winding wound around said magnetic core. and an electrostatic shielding cylinder provided around said winding, and the axis of said magnetic core is coinsided with a perpendicular dropped from the bottom surface of the car body onto the surface of the ground.
  • receiver antenna is a bar-shaped receiver antenna, and said antenna is substantially arranged along the axle di rection of the car body.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Support Of Aerials (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)
  • Measuring Fluid Pressure (AREA)
US491902A 1973-09-10 1974-07-25 System for transmitting information of reduced pneumatic pressure of tire Expired - Lifetime US3895347A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP10196273A JPS5441338B2 (de) 1973-09-10 1973-09-10
JP628774A JPS5621197B2 (de) 1974-01-10 1974-01-10

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US3895347A true US3895347A (en) 1975-07-15

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US491902A Expired - Lifetime US3895347A (en) 1973-09-10 1974-07-25 System for transmitting information of reduced pneumatic pressure of tire

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GB (1) GB1483095A (de)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4240061A (en) * 1978-03-04 1980-12-16 Dunlop Limited Devices for the measurement of the physical state of a pneumatic tire
US4254398A (en) * 1977-09-29 1981-03-03 Bridgestone Tire Company Limited Tire pressure drop alarming apparatus
US4300118A (en) * 1978-02-28 1981-11-10 Bridgestone Tire Company Limited Tire inner pressure drop alarming service
US4328479A (en) * 1978-06-26 1982-05-04 Matra, A French Society Installation for detecting anomalies in inflating of the tires of a guided vehicle
US4352090A (en) * 1981-01-30 1982-09-28 Satoru Ohama Detection and alarm device for use with car for detecting obstacle and abnormal conditions of tire
US5231391A (en) * 1990-11-30 1993-07-27 Skf France Passive pick-up device for monitoring the state of the tire of a vehicle wheel and measuring the rotation characteristics of the wheel
US5663496A (en) * 1993-08-03 1997-09-02 The Mclaughlin Group Tire monitoring via an electromagnetic path including the ground plan of a vehicle
US5673018A (en) * 1995-06-07 1997-09-30 Palomar Technologies Corporation Transponder system for reporting the distance traveled by a wheeled vehicle
WO1997036758A2 (en) * 1996-03-29 1997-10-09 Michael Handfield System and method for monitoring a pneumatic tire
US5969239A (en) * 1995-08-08 1999-10-19 Compagnie Generale Des Etablissments Michelin - Michelin & Cie Device for monitoring the tires of a vehicle with electromagnetically coupled antennas
US6474380B1 (en) * 1999-04-29 2002-11-05 Bridgestone/Firestone North American Tire, Llc Pneumatic tire and monitoring device including dipole antenna
US20050188757A1 (en) * 2004-02-27 2005-09-01 Trw Automotive U.S. Llc Tire parameter sensing system having a magnetically conductive rim and an associated method
US20060010992A1 (en) * 2002-06-21 2006-01-19 Hiroshi Shima Method for measuring forces acted upon tire and apparatus for measuring forces acted upon tire
US20060061462A1 (en) * 2003-04-02 2006-03-23 The Yokohana Rubber Co., Ltd. Communication system for tire
US20060279448A1 (en) * 2005-06-08 2006-12-14 Via Technologies, Inc. Cyclic pipeline analog to digital converter with enhanced accuracy
US20070103285A1 (en) * 2005-11-04 2007-05-10 Alps Electric Co., Ltd. Antenna apparatus disposed in tire
US20070117815A1 (en) * 2005-11-04 2007-05-24 James Pluda Method of treating cancers with SAHA and pemetrexed
US20070144248A1 (en) * 2005-12-27 2007-06-28 Pacific Industrial Co., Ltd. Tire information communication system
US20070198150A1 (en) * 2004-03-12 2007-08-23 Manabu Kato System For Monitoring Condition Of Wheel
EP1841087A1 (de) * 2006-03-31 2007-10-03 Pacific Industrial Co., Ltd. Datenkommunikationssystem

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Publication number Priority date Publication date Assignee Title
JPS611515Y2 (de) * 1978-06-20 1986-01-18
GB2358949A (en) * 2000-02-03 2001-08-08 Transense Technologies Plc Tyre monitoring system

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US3533063A (en) * 1966-12-09 1970-10-06 George E Garcia Low pressure pneumatic tire transmitter
US3835451A (en) * 1972-09-15 1974-09-10 Tyrechek Inc Pulse stretcher for a receiver of a pneumatic tire low pressure monitoring and warning system

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Publication number Priority date Publication date Assignee Title
US3533063A (en) * 1966-12-09 1970-10-06 George E Garcia Low pressure pneumatic tire transmitter
US3835451A (en) * 1972-09-15 1974-09-10 Tyrechek Inc Pulse stretcher for a receiver of a pneumatic tire low pressure monitoring and warning system

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4254398A (en) * 1977-09-29 1981-03-03 Bridgestone Tire Company Limited Tire pressure drop alarming apparatus
US4300118A (en) * 1978-02-28 1981-11-10 Bridgestone Tire Company Limited Tire inner pressure drop alarming service
US4240061A (en) * 1978-03-04 1980-12-16 Dunlop Limited Devices for the measurement of the physical state of a pneumatic tire
US4328479A (en) * 1978-06-26 1982-05-04 Matra, A French Society Installation for detecting anomalies in inflating of the tires of a guided vehicle
US4352090A (en) * 1981-01-30 1982-09-28 Satoru Ohama Detection and alarm device for use with car for detecting obstacle and abnormal conditions of tire
US5231391A (en) * 1990-11-30 1993-07-27 Skf France Passive pick-up device for monitoring the state of the tire of a vehicle wheel and measuring the rotation characteristics of the wheel
US5663496A (en) * 1993-08-03 1997-09-02 The Mclaughlin Group Tire monitoring via an electromagnetic path including the ground plan of a vehicle
US5741966A (en) * 1993-08-03 1998-04-21 Handfield; Michael Method and system for monitoring a parameter of a vehicle tire
US5673018A (en) * 1995-06-07 1997-09-30 Palomar Technologies Corporation Transponder system for reporting the distance traveled by a wheeled vehicle
US5969239A (en) * 1995-08-08 1999-10-19 Compagnie Generale Des Etablissments Michelin - Michelin & Cie Device for monitoring the tires of a vehicle with electromagnetically coupled antennas
WO1997036758A2 (en) * 1996-03-29 1997-10-09 Michael Handfield System and method for monitoring a pneumatic tire
WO1997036758A3 (en) * 1996-03-29 1997-11-06 Michael Handfield System and method for monitoring a pneumatic tire
US6474380B1 (en) * 1999-04-29 2002-11-05 Bridgestone/Firestone North American Tire, Llc Pneumatic tire and monitoring device including dipole antenna
US7302868B2 (en) * 2002-06-21 2007-12-04 Bridgestone Corporation Method for measuring forces acted upon tire and apparatus for measuring forces acted upon tire
US20060010992A1 (en) * 2002-06-21 2006-01-19 Hiroshi Shima Method for measuring forces acted upon tire and apparatus for measuring forces acted upon tire
US7253784B2 (en) * 2003-04-02 2007-08-07 The Yokohama Rubber Co., Ltd. Communication system for tire
US20060061462A1 (en) * 2003-04-02 2006-03-23 The Yokohana Rubber Co., Ltd. Communication system for tire
US6938468B1 (en) 2004-02-27 2005-09-06 Trw Automotive U.S. Llc Tire parameter sensing system having a magnetically conductive rim and an associated method
US20050188757A1 (en) * 2004-02-27 2005-09-01 Trw Automotive U.S. Llc Tire parameter sensing system having a magnetically conductive rim and an associated method
US20070198150A1 (en) * 2004-03-12 2007-08-23 Manabu Kato System For Monitoring Condition Of Wheel
US20060279448A1 (en) * 2005-06-08 2006-12-14 Via Technologies, Inc. Cyclic pipeline analog to digital converter with enhanced accuracy
US20070103285A1 (en) * 2005-11-04 2007-05-10 Alps Electric Co., Ltd. Antenna apparatus disposed in tire
US20070117815A1 (en) * 2005-11-04 2007-05-24 James Pluda Method of treating cancers with SAHA and pemetrexed
US20070144248A1 (en) * 2005-12-27 2007-06-28 Pacific Industrial Co., Ltd. Tire information communication system
US7251993B1 (en) * 2005-12-27 2007-08-07 Pacific Industrial Co., Ltd. Tire information communication system
EP1841087A1 (de) * 2006-03-31 2007-10-03 Pacific Industrial Co., Ltd. Datenkommunikationssystem
US20070227240A1 (en) * 2006-03-31 2007-10-04 Pacific Industrial Co., Ltd. Data communication system
US7737834B2 (en) 2006-03-31 2010-06-15 Pacific Industrial Co., Ltd. Data communication system

Also Published As

Publication number Publication date
DE2443046B2 (de) 1978-07-13
DE2443046A1 (de) 1975-04-30
DE2443046C3 (de) 1979-03-22
GB1483095A (en) 1977-08-17

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